Changeling: still not perfect?

[thefiremind]

I just had the crazy idea of making a changeling deck, with many changelings together with the best "lords" of the creature types (Goblin Warchief and similar). But then I thought: does changeling really work as it should in DotP2013? After all, we have only 1 example (Chameleon Colossus) in a deck that doesn't really care about creature types.

Just for a start, the original Chameleon Colossus lacks of active_zone="ZONE_ANY" in his changeling ability, while changeling should work in all zones. I hope that adding active_zone="ZONE_ANY" is enough to take care of this (I didn't try yet).

This is a good place to find the correct rules:
http://wiki.mtgsalvation.com/article/Changeling
Let's check them one by one:

Because a card with changeling is every creature type, it will be affected by any spell or ability that affects any creature type, regardless of what that creature type is. And because changeling is a characteristic-defining ability, this is true in all zones. For example, if a card tells you to reveal a Merfolk card from your hand, return a Goblin card from your graveyard to your hand, or gain control of a Goat, you can perform these actions on a card with changeling.

OK, this should be achieved with active_zone="ZONE_ANY".

If an effect causes a creature with changeling to lose all creature types, the creature won't lose changeling -- but it will lose all its creature types.

This should work since we aren't assigning a layer to static abilities that are always active on the card, so the "type gain" should be correctly cancelled by the "type loss" (it should be tested anyway).

If an effect causes a creature with changeling to become a new creature type or types, the creature won't lose changeling -- but it won't have all creature types anymore. It will be just the new creature type(s).

Same as the previous rule.

If a card loses the changeling ability, it will still have all creature types. It just won't have changeling.

This is a problem! It just can't be achieved, since it's the ability itself that grants the creature types. The LoseAllAbilities function will probably have a wrong effect on a changeling.

Note that effects that grant an object all creature types do *not* give that object changeling.

And this is another problem: if we code something that grants all creature types we have to use changeling because there's no other way (giving all creature types one by one had strange side-effects on DotP2012, so I would strongly discourage anyone from doing it).

The question is: did someone else make some tests on the changeling ability? If so, what were the results?